Verbose garbage collection in JVM logs

Verbose garbage collection (verbosegc) logging is often required when tuning and debugging many issues, particularly memory problems, and has negligible impact on system performance.

The default WebSphere Portal installation enables verbose garbage collection (verbosegc) logging and configures the following generic JVM argument:

-Xverbosegclog:${SERVER_LOG_ROOT}/verbosegc.m%d.5/2/12M%S.%pid.txt,20,10000

The verbosegc log file name is verbosegc.m%d.5/2/12M%S.%pid.txt. It includes a date/time stamp and the process id (pid) of the WebSphere Portal instance.

The default WebSphere Portal installation redirects the verbosegc output to 20 rotating historical log files, each containing 10000 garbage collection (GC) cycles.

For more information about configuring the JVM through WAS, see the IBM WAS information centers at www.ibm.com/software/webservers/appserv/was/library.

For more information about JVM argument -Xverbosegclog, see Java Diagnostic Guides at www.ibm.com/developerworks/java/jdk/diagnosis/60.html.

Parent: Logging and tracing